Floating cover with structural supports

ABSTRACT

A floating cover for a body of water has a flexible, impermeable substrate with a bottom face and a top face opposite the bottom face. The substrate is secured laterally across the surface of the body of water while being permitted to move vertically as the level of the body of water changes. A float is affixed to the bottom face of the substrate and a structure is rigidly mounted above the float. The structure extends above the top face of the substrate. The substrate is sealed between the float and the structure. The buoyant force of the float acts against the weight of the structure to maintain the substrate immediately adjacent to the float above the top surface of the body of water so as not to interfere with precipitation drainage.

TECHNICAL FIELD

This relates to floating covers, and in particular, floating covers thatsupport structures on a top surface.

BACKGROUND

Floating covers are commonly used on bodies of water, such asreservoirs, lagoons, ponds, sloughs, etc., as a cover to preventevaporation, prevent contamination of the water, to capture gas producedby the water, or to reduce odours. As used herein, the term “water” isused in a broad sense to cover various types of bodies of liquid thatmay be covered by a floating cover as is known in the art. This mayinclude water or water-based liquids, which may vary from relativelypure sources, such as water that may be used for a municipal watersupply, to relatively impure sources, such as effluent or grey-waterfrom a sewage system.

Typical floating covers are generally held under tension to resistlateral movement, while permitting the cover to move vertically as thelevel of water changes. In order to address water that may accumulatedue to precipitation, floating covers may have a sump that allows waterto be drawn off the cover. U.S. Pat. No. 3,815,367 (Collins et al.) andU.S. Pat. No. 3,815,367 (Collins et al.), each entitled “FloatingReservoir Cover” are early examples of floating covers with tensioners.U.S. Pat. No. 3,991,900 (Burke et al.) entitled “Reservoir Cover andCanalizing Means” describes a floating cover that is tensioned byweights, that also form a sump. Various devices and designs for floatingcovers have been used and are known in the art.

SUMMARY

There is provided an improved tensioned floating cover that supports astructure. The floating cover comprises a flexible, inelastic,impermeable substrate, the substrate having a bottom face and a top faceopposite the bottom face, the substrate extending laterally across asurface of a body of water. The floating cover has one or moretensioners that apply tension to a tensioned section of the substrateand bias the tensioned section of the substrate to an installed positionon the body of water, the tensioners permitting the substrate to movevertically on a top surface of the body of water as the volume of waterin the body of water changes. The floating cover also has aprecipitation drainage system for removing water from the top face ofthe substrate. The tensioned floating cover is characterized in thatthere are a plurality of floats affixed to the bottom face of thetensioned section of the substrate, each float having a planar upperprofile and a buoyant force in water, wherein each float is spaced fromadjacent floats and dimensioned such that in use, the buoyant forcemaintains the upper profile of the float at a non-disruptive heightabove the surface of the body of water, the non-disruptive height beinga height at which water flow to the precipitation drainage system is notdisrupted. One or more structures are rigidly mounted above two or morefloats and extend above the top face of the substrate in an uprightorientation, the substrate being sealed between the float and thestructure, the structure having a weight, wherein the buoyant force ofthe float acts against the weight of the structure to maintain thesubstrate immediately adjacent to the float above the surface of thebody of water. The one or more tensioners apply sufficient force tomaintain the spacing between adjacent floats and to maintain thestructures in the upright orientation when acted upon by a predeterminedwind load.

According to another aspect, there is provided a floating cover for abody of water, comprising a flexible, inelastic, impermeable substratehaving a bottom face and a top face opposite the bottom face, thesubstrate being secured laterally across the top surface; one or moretensioners that apply at least 0.5 lb/lineal foot of tension to create atensioned section of the substrate; a precipitation drainage system forremoving water from the top face of the substrate; a plurality of floatshaving a substantially planar upper profile, the upper profile beingaffixed to the bottom face of the tensioned section of the substrate,the float having a buoyant force in water; and a structure rigidlymounted above one or more floats, the structure extending above the topface of the substrate, being sealed between the float and the structureand having a weight, wherein the buoyant force of the float acts againstthe weight of the structure to maintain the substrate immediatelyadjacent to the float above the top surface of the body of water by 4inches or less, or 2 inches or less.

According to an aspect, there is provided an improved tensioned floatingcover that supports a structure, the floating cover comprising aflexible, inelastic, impermeable substrate, the substrate having abottom face and a top face opposite the bottom face, the substrateextending laterally across a surface of a body of water, the substratebeing made from a material that has a tensile strength of at least 100lb/inch. There are one or more tensioners that apply tension to atensioned section of the substrate and bias the tensioned section of thesubstrate to an installed position on the body of water, the tensionerspermitting the substrate to move vertically on a top surface of the bodyof water as the volume of water in the body of water changes. There is aprecipitation drainage system for removing water from the top face ofthe substrate. The tensioned floating cover is characterized in thatthere are a plurality of floats affixed to the bottom face of thetensioned section of the substrate in a linear or two-dimensional array,each float having a planar upper profile, a buoyant force in water, anda width that is at least 10 times greater than the height, wherein eachfloat is spaced from adjacent floats and dimensioned such that in use,the buoyant force maintains the upper profile of the float at anon-disruptive height above the surface of the body of water, thenon-disruptive height being a height at which water flow to theprecipitation drainage system is not disrupted. A plurality ofstructures are rigidly mounted above a plurality of floats distributedabout the substrate, the structures extending above the top face of thesubstrate in an upright orientation, the structure being mounted abovethe float by a mounting comprising an adhesive mounting, a mechanicalmounting, welding, or combination thereof, such that the substrate issealed between the float and the structure, the structure having aweight, wherein the buoyant force of the float acts against the weightof the structure to maintain the substrate immediately adjacent to thefloat above the surface of the body of water. The one or more tensionersapply sufficient force to maintain the spacing between adjacent floatsand to maintain the structures in the upright orientation when actedupon by a predetermined wind load.

In other aspects, the floating covers may further comprise one or moreof the following features, alone or in combination: the floats may bearranged in a linear or two-dimensional array, the substrate may be madefrom a material that has a tensile strength of at least 100 lb/inch; thebuoyant force may maintain the substrate immediately adjacent to thefloat above the top surface by 4 inches or less, or 2 inches or less;the float may have a height of less than 6 inches, and a volumeextending perpendicular to the height sufficient to provide the buoyantforce; the float may have a width that is at least 10 times greater thanthe height; the float may comprise a moulded body, a hollow body, a foamfilled body, or a laminated structure; the float may comprise ballastthat has a density that is greater than or equal to water; the float maybe laminated to the bottom face of the substrate; the float may beenclosed within a cavity formed by a second layer of material attachedto the bottom face of the impermeable substrate; the structure may bemounted above the float by a mounting comprising an adhesive mounting, amechanical mounting, welding, or combination thereof; there may be aplurality of structures mounted to a plurality of floats distributedabout the substrate; the structure may comprise a body supported abovethe substrate by a stand; the stand may comprise an assembled frame or amoulded frame, and the body may be supported by a plurality of standsmounted above a plurality of floats; the structure may comprise asupport for elongate bodies, a walkway, an access ramp, a workingplatform, a shelter, a solar module, a decorative element, a shadestructure for the body of water, a thermal collector, an aerator, awater cooler, or a pump; the tensioner may comprise length adjustableelements distributed along an outer peripheral edge of the substrate;the tensioner may comprise weights distributed about the top face of thesubstrate; the substrate may comprise a plurality of substrate sectionssealably attached to form the substrate; the floating cover may furthercomprise stabilizing supports connected between adjacent structures tosupport the structures against wind pressure; the floating cover mayfurther comprise a plurality of floats and structures, and thestabilizing supports may be connected between adjacent structures; theremay be a plurality of floats and structures, and the stabilizingsupports may be connected between adjacent floats; the floating covermay further comprise one or more anchors, which may be buoyant orneutrally buoyant in water, affixed to the substrate, and thestabilizing supports may connect between the one or more anchors and thestructure or between the one or more anchor and the float; the forceapplied by the tensioners may permit the substrate to shift under windloads greater than the predetermined wind load, and return the substrateto the predetermined position relative to the body of water after thewind load is reduced to below the predetermined wind load.

According to another aspect, there is provided a method of mounting astructure above a floating cover, the method comprising the steps of:providing a floating cover as described above, having a plurality ofsubstrate sections of a flexible, inelastic, impermeable substrate, thesubstrate sections with a top face, a bottom face, and parallel sideedges separated by a width; affixing a plurality of floats to the bottomface of one or more substrate sections, the floats having a buoyantforce in water, the floats being low profile and having a substantiallyplanar upper profile that engages the substrate; rigidly mountingstructures to the floats such that the structures extend away from thefloats and the top face of the one or more substrate sections; attachingthe plurality of substrate sections in edge to edge relation along theparallel side edges to form the substrate, the floats having a heightrelative to the width of the at least one section that permits adjacentsubstrate sections to be attached in edge to edge relation withoutinterfering with the attachment between edges to form a sealed surface;installing the substrate on a reservoir and filling the reservoir toform a body of water having a surface; applying tension to the substrateto at least that portion of the substrate to which floats are affixed,the applied tension being sufficient to maintain the spacing betweenadjacent floats and to maintain the structures in the uprightorientation when acted upon by a predetermined wind load.

According to an aspect, there is provided a method of mounting astructure above a floating cover, the method comprising the steps of:providing a plurality of substrate sections of a flexible, inelastic,impermeable substrate, the substrate sections having a top face, abottom face, and parallel side edges separated by a width; affixing aplurality of floats to the bottom face of one or more substratesections, the floats having a buoyant force in water, the floats beinglow profile and having a substantially planar upper profile that engagesthe substrate; rigidly mounting structures to the floats such that thestructures extend away from the floats and the top face of the one ormore substrate sections; attaching the plurality of substrate sectionsin edge to edge relation along the parallel side edges to form thesubstrate; installing the substrate on a reservoir and filling thereservoir to form a body of water having a surface, such that the upperprofile of the floats is maintained at a non-disruptive height above thesurface of the body of water, the non-disruptive height being a heightat which water flow to the precipitation drainage system is notdisrupted; and applying tension to the substrate to at least thatportion of the substrate to which floats are affixed, the appliedtension being sufficient to maintain the spacing between adjacentfloats, to maintain the structures in the upright orientation, andmaintain the substrate in a predetermined position relative to the bodyof water when acted upon by a predetermined wind load, the appliedtension permitting the substrate to shift under wind loads greater thanthe predetermined wind load, and returning the substrate to thepredetermined position relative to the body of water after the wind loadis reduced to below the predetermined wind load.

According to other aspects of the method described above, the floats maybe affixed to the one or more substrate sections with the one or moresubstrate sections inverted; and the one or more substrate sections towhich the floats are affixed may be prepared with the floats and atleast a portion of the structures offsite.

In other aspects, the features described above may be combined togetherin any reasonable combination as will be recognized by those skilled inthe art.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features will become more apparent from the followingdescription in which reference is made to the appended drawings, thedrawings are for the purpose of illustration only and are not intendedto be in any way limiting, wherein:

FIG. 1 is a top plan view of a pond.

FIG. 2A is a top plan view of a pond covered by a floating covertensioned by weights.

FIG. 2B is a top plan view of a pond covered by a floating cover andsupporting structures in a two dimensional array.

FIG. 3A is a top plan view of a pond covered by a floating covertensioned by elongate members attached to a tower.

FIG. 3B is a top plan view of a pond covered by a floating cover andsupporting structures in a linear array.

FIG. 4 is a side elevation view of a floating cover with two floatssupporting two structures.

FIG. 5 is a side elevation view a floating cover with two floatssupporting one structure.

FIG. 6 is a side elevation view of a floating cover with a floatsupporting a structure and a perimeter anchor that provides acounterbalance.

FIG. 7 is a side elevation view of a floating cover with two floatssupporting two structures and connected by a connector.

FIG. 8 is a side elevation view of a floating cover with one floatsupporting a structure directly on the cover.

FIG. 9 is a side elevation view of a floating cover with the floatcontained in a pocket of the cover.

FIG. 10 is a side elevation view of a floating cover with a floatsupporting a structure having a portion that extends below the cover.

FIG. 11 is a side elevation view of a floating cover having a tensioningstructure with floats and a weighted sump area.

FIG. 12 is a side elevation view of a floating cover tensioned by anelongate member.

FIG. 13 is a perspective view of a high aspect ratio float.

FIG. 14 is a cross-sectional view of an anchor partially filled withballast.

FIG. 15 is a side elevation view of a pond having a weight tensionedfloating cover.

FIG. 16 is a side elevation view of a pond having a floating covertensioned by an elongate member.

FIG. 17 is a side elevation view of a section of the floating coversubstrate folded over floats.

FIG. 18 is a perspective view of a section of the floating cover,preformed with holes, and being unrolled over the floats.

DETAILED DESCRIPTION

There will now be described a floating cover, generally identified byreference number 10, that is designed to support a structure 12 above abody of water 16, without affecting the ability of floating cover 10 tooperate as such.

FIG. 1 shows a body of water 16, which may be a pond or other body ofwater. Referring to FIGS. 2A, 2B, 3A, and 3B, there is shown a floatingcover 10 made from a substrate 14 that is used to cover body of water16. Substrate 14 is made from a material that is flexible, inelastic,and impermeable. An example of a suitable material is CSPE 45 mil, 3ply(chlorosulphonated polyethylene), which has a tensile strength of about100 lb/inch. Other material may be used with suitable properties as maybe selected by a person of ordinary skill. Preferably, the lineartensile strength will be at least 100 lb/inch, or sufficient to supportthe various loads, including wind loads, etc., without failing.Substrate 14 may be assembled from different materials for differentareas, and may be stronger, to account for different load that may beexperienced by substrate 14. While there are various degrees offlexibility and elasticity, substrate 14 may be considered flexible ifit can be rolled or folded into a package for storage or transport, andmay be considered inelastic if there is a negligible amount ofstretching across its length under typical wind loads that may beexperienced by floating cover 10.

Substrate 14 is tensioned in order to hold substrate 14 laterally onbody of water 16 and allows substrate 14 to move vertically as thevolume of water in the body of water 16 changes. Preferably, the tensionis applied by a tensioner that is able to adjust, move, or otherwiseadapt to movement, such as a length-adjustable spring member or weight,either on substrate 14 or along an outer perimeter 18 of substrate 14.By using adaptable tensioners, substrate 14 is able to adjust by takingin any slack as the level of body of water 16 rises, or allow more slackout as the level goes down. Various types of tensioners as known in theart may be used. For example, referring to FIG. 12, the tensioners aretowers 15 with weights on pulleys inside the towers (not shown),positioned around outer perimeter 18 of substrate 14. Alternatively,tensioners may take other designs using elongate members, such astensioning springs. Referring to FIG. 11, the tensioners may be weights19 distributed on top surface 20 of substrate 14. As shown, weights 19take up any slack in substrate 14 by sinking, or deploying slack bymoving up. Preferably, weights 19 are installed in a line with floats 24on the top surface 20 of substrate 14 on either side of weights 19,which keeps substrate 14 that is adjacent to weights 19 on top of bodyof water 16, rather than sinking with weights 19.

Substrate 14 is also provided with a precipitation drainage system, suchas sump 22 as shown in FIG. 2A and FIG. 2B or drain line 23 as shown inFIGS. 3A and 3B, in order to remove water from top face 20 of substrate14. Generally speaking, the most common type of water that will be foundon top of substrate 14 will be from precipitation, although sump 22 willbe capable of draining any liquid on the top of substrate 14. As shown,sump 22 includes a pump 26 that is in fluid communication with thedepressions caused by weights 19. Weights 19 may be part of thetensioning system as shown in FIG. 2, or may be at a fixed depth, andmay be solely for the purpose of creating channels that allow water toflow to sump pump 26, which will be in a depression that is even lowerthan weights 19, and allow water to be pumped off of substrate 14,either under substrate 14 into body of water 16 or away from body ofwater 16. While one pump 26 is shown at each of the intersections of thechannels, there may be any number of pumps 26, depending on therequirements of the particular floating cover 10. As an alternative tosump 22 or drain line 23, persons of ordinary skill may use otherdrainage systems as are known in the art.

The tension and drainage aspects described above are generally known inthe art and are commonly used in floating covers installed on bodies ofwater. As will be described herein, floating cover 10 differs from priorart floating covers in its ability to support a structure abovesubstrate 14 without preventing floating cover 10 from operating as afloating cover 10. In particular, floating cover 10 remains a sealed,impermeable cover, and allows water to be drained off of top face 20 ofsubstrate 14. As described below, floating cover 10 has an area 32 onwhich the structures are installed, which includes a tensioned sectionof substrate 14. The characteristics of area 32 may depend on the designof floating cover 10 as well as the characteristics of body of water 16,such as the angle of the sides of body of water 16. As an example, inorder to maintain a suitable spacing and position for the structure,area 32 may be defined by weights 19, either as part of sump 22 or asused as a tensioning device, where weights 19 are shown in a squareconfiguration. Other shapes may also be used, or there may be more thanone area 32, which may be separated by weights 19. Alternatively, ifweights are not used, area 32 may include the entire substrate 14, or atleast that area that will remain in contact with water, and not liftedoff body of water 16 as the level of body of water 16 changes. Thedetails of how the structures are installed on substrate 14 will bedescribed below.

Referring to FIGS. 2B and 3B, floating cover 10 is provided with aplurality of support floats 30 that are affixed to the bottom face 34 ofarea 32 in spaced relation, and which are positioned below structures 12in order to support them above substrate 14. Referring to FIG. 4, eachfloat 30 has a buoyant force in water, with a planar upper profile 36. Asuitable shape for float 30 is a rectangular prism, with a height thatis significantly less than its width and length. In one example, theheight may be less than 1/10 of either the width or the length, and maybe 6 inches or less. However, the dimensions of float 30 will depend onthe preferences of the user and the characteristics of floating cover10, including the weight of structure 12 and any tension that may beapplied by substrate 14.

The height of float 30 when installed will depend on the buoyant forceof float 30 and the load applied from above. The height must besufficient to support substrate 14 at or above the surface of body ofwater 16. If float 30 does not support substrate 14 at or above body ofwater 16, there is a risk that substrate 14 may have low points whichcan then accumulate surface water due to precipitation, etc. Preferably,substrate 14 will be supported at least a small amount above body ofwater 16 to allow for some tolerance for error. However, at the sametime, if substrate 14 is lifted above a maximum height above the topsurface of body of water 16, floats 30 will disrupt the flow of watertoward sump 22 by creating creases or other contours in the inelasticsubstrate 14. This will also result in water accumulating abovesubstrate 14. Any accumulation of water on substrate 14 is to be avoidedas, once water starts to accumulate in an undesired location, a depositof dust, dirt, etc., will begin to accumulate as the water evaporates.The dust and dirt will increase the weight in that area, such that morewater will accumulate in that area, and continue to increase the weightin that area, and will ultimately result in the failure of floatingcover 10, either structurally or in its purpose, if corrective action isnot taken. In a preferred embodiment, float 30 will extend between ⅛ and4 inches above the surface of body of water 16, or in some cases between⅛ and 2 inches.

Floats 30 are spaced from each other, and are preferably in a twodimensional array as shown in FIG. 2B, or a one dimensional array asshown in FIG. 3B, in order to provide a suitable platform on whichstructures 12 may be mounted. Structure 12 is mounted to floats 30 suchthat structure 12 extends above the top face 20 of substrate 14 in anupright orientation, and such that substrate 14 is sealed between float30 and structure 12 to ensure substrate 14 remains sealed andimpermeable across body of water 16. The buoyant force of float 30 actsagainst the weight of structure 12 to maintain substrate 14 that isimmediately adjacent to float 16 above the surface of body of water 16.Floats 30 may take various forms as is known in the art, and may be amoulded body, a hollow body, a foam-filled body, a solid body with a lowdensity, a laminated or composite structure, etc. Referring to FIG. 14,float 30 may be a composite structure that includes ballast 37 that isdenser or of the same density as water, to reduce the buoyancy of float30 in water. This may be used to control the height of float 30 inwater, to increase the stability of float 30, or to act as an anchorinstead of or in addition to a float, as will be described below.

Float 30 may be mounted to substrate 14 in different ways. Referring toFIG. 4, float 30 and substrate 14 may be laminated together atattachment 38, such as by an adhesive or the application of heat, or maybe attached at attachment 38 by using a mechanical attachment, such as apin connector or other type of attachment that extends through substrate14, and may attach to structure 12. If mechanical attachment is designedto extend through substrate 14, it should be done in such a way thatsubstrate 14 remains sealed against water passing through in eitherdirection. Referring to FIG. 9, float 30 may also be installed in acavity 39 that is formed by a second layer of material 14 a that isattached to bottom face of substrate 14. Cavity 39 may be sufficientlyrestrictive and second layer 14 a sufficiently strong to affix float 30relative to substrate 14. If required, an additional attachment may beused to affix float 30 to substrate 14. Second layer 14 a need not bethe same material as substrate 14, and may not have the samecharacteristics. For example, it may not be impermeable.

As shown, structure 12 extends above substrate 14. In doing so,structure 12 is mounted above float 30, either directly to float 30 orto substrate 14, by various mounting structures, such as by adhesive orheat welding to substrate 14 as shown in FIG. 8, or by mechanicalmounting, as shown in FIG. 4. Structure 12 may take various forms, suchas a single structure that is supported by multiple floats 30 as shownin FIG. 5, or multiple structures, each of which is supported by one ormore floats 30 as shown in FIG. 4. Structure 12 may be a unitary body asshown in FIG. 8, or, referring to FIG. 4, structure 12 may include astand 40 that supports a body 42 above substrate 14. Stand 40 may be aframe as shown, which may be an assembled frame, or a moulded frame, ormay be a solid or hollow body. The composition of structure 12 willdepend on purpose of structure 12, its size and weight, theenvironmental conditions in which it will be used, etc. In the exampleshown in FIG. 5, there are multiple stands 40 that support an elongatebody 42 that extends across the multiple stands 40, such as a pipeline.In other examples, referring to FIG. 7, body 42 may be a walkway forworkers, a working platform, an access ramp, a shelter or building,etc., that are either mounted to one or more stands 40, or directly onsubstrate 14 above floats 30. On other examples, referring to FIG. 8,structure 12 may include a single body 42 a mounted above a single float30, such as solar module, a decorative element, a shade structure forthe body of water, a thermal collector, a water cooler, a pump, etc., ormay be used to support equipment 54 below substrate 14, such as a pumpor aerator. It will be understood that each type of structure 12described above may be mounted to one float 30, or more than one float30, and each may be mounted to a stand above float 30, or mounteddirectly to float 30, depending on various factors, such as thepreferences of the user, the construction of structure 12, its size, itsweight, etc.

As noted above, the spacing between floats 30 is maintained at a desireddistance, which is at least partly accomplished by properly tensioningsubstrate 14. The tension is designed to apply sufficient force tomaintain the spacing between adjacent floats 30 and to maintainstructures 12 in an upright orientation when acted upon by environmentalconditions, and in particular, a predetermined wind load. Thepredetermined wind load may be the wind loads that are typical for theenvironment in which cover 10 is installed based on average conditions,or somewhat more than the typical wind loads to provide a measure ofadditional protection against exceptional winds that may be encountered.Alternatively, floating cover 10 may be tensioned sufficiently towithstand the maximum possible wind loads that may be experienced byfloating cover 10. For example, in any given year, an area mayexperience wind gusts of up to 40 mph, but may experience wind gust ofup to 70 mph on rare occasions. Floating cover 10 may be tensionedsufficiently to withstand a 40 mph wind gust without moving, and may bedesigned to allow for some movement in exceptionally high windconditions, or may be tensioned sufficiently to withstand even anexceptional wind event with wind loads that are higher than normal. Inany event, floating cover 10 will be designed to recover from themaximum level of wind loads that may be applied. This may involveallowing substrate 14 to shift laterally across body of water 16, and toallow some tipping movement of structure 12, but allowing floating cover10 to return to its original position once the exceptional wind eventhas ended. Of these consequences, lateral movement of 14 is relativelymore acceptable that allowing structure 12 to move too much, as themovement of structure 12 may result in damage to structure 12 orsubstrate 14.

In order to enhance the resistance to wind loads in floating cover 10,certain strategies may be used and additional elements installed. Asnoted above, two main considerations with respect to the reaction offloating cover 10 to wind loads are the lateral movement of substrate 14in response to wind loads, and the movement of structures 12 in responseto wind loads. Preferably, substrate 14 will be sufficiently anchored toprevent lateral movement, or at least limited to extreme weather events.There may be some advantages to allowing substrate 14 to move laterallyduring extreme weather events, including a reduction in the cost ofequipment and installation. Of greater concern is the possible movementof structures 12 relative to substrate 14. Structures 12 must besufficiently supported by substrate 14 (e.g. via floats 30) such thatthey remain attached even during extreme weather events. Structures 12must also be sufficient supported to prevent tipping as a result of windloads. While it is impossible to prevent all movement in structure 12,any movement that is permitted must be limited to movement that will notcause damage to floating cover 10, e.g. either structure 12 substrate14, or floats 30.

If the tension in substrate 14 is insufficient to accomplish the abovepurposes, floating cover 10 may be provided with various types ofstabilizing supports that support structure 12 against wind pressure.Generally speaking, the stabilizing supports act to lower the centre ofgravity of structure 12, increase the moment arm required to tipstructure 12, transfer loads to an adjacent structure, etc.

In one example, the stabilizing supports may be connectors 44 thatconnect between adjacent structures 12 or floats 30. Connectors 44 mayextend diagonally from top to bottom of adjacent structures 12 or floats30, or may connect horizontally between structures 12 or floats 30,either above or below substrate 14. If connectors 44 are above substrate14, as shown in FIG. 7, care must be taken to avoid weighting substrate14 in such a way that it will interfere with water flow across substrate14. As structures 12 begin to tip, one end or edge will go up, andanother will go down. As the wind load will generally be in the samedirection across all of floating cover 10, or at least within the samelocalized area, adjacent structures 12 will tilt in the same direction,meaning adjacent edges will move in opposite directions. By connectingadjacent structures 12 or floats 30 with inelastic connectors 44, theconnectors 44 will be placed under tension and will resist the tippingmovement of structures 12. Connectors 44 are preferably rigid, and maybe made from a variety of materials, depending on the preferences of theuser. As noted previously, substrate 14 is tensioned, which biasesfloats 30 into a predetermined array.

In another example, referring to FIG. 6, anchors 46 may be affixed tosubstrate 14. Anchors 46 are preferably weighted to resist substrate 14from being lifted, but may have a sufficiently low overall density to bebuoyant in water to prevent pulling down on substrate 14 if notsufficiently supported in other ways. Anchors 46 are preferablypositioned beneath substrate 14 and around the perimeter of the array offloats 30 to provide stability to floats 30, substrate 14, andultimately structures 12. Anchors 46 may be attached in various ways,similar to the manner in which floats 30 are attached to substrate 14.The weight and buoyancy of anchors 46 will be selected such that they donot extend above the surface of body of water 12 in such a way as tointerfere with the flow of water across substrate 14. In one example,anchors 46 may be neutrally buoyant, such that they are sufficientlybuoyant to have a low profile in water without sinking, and such thattheir weight is only apparent when anchors 46 are lifted out of water.As they have a low profile above the water level of body of water 16,anchors 46 will have little impact on wind loads and water flow, butwill be useful in supporting structures 12. Anchors 46 may be attachedby connectors 44 to adjacent structures or floats 30, and providesimilar benefits to those described above, although without acorresponding structure 12 above anchor 46. Alternatively, or inaddition, there may be mechanical anchors (not shown) that attachbetween floats 30 or anchors 46 and the bottom of the body of water toassist in anchoring structures 12 and substrate 14.

Method of Construction

An example of construction for floating cover 10 will now be described.Referring to FIG. 2, for bodies of water 16 with a large surface area,typical covers are commonly prepared by attaching multiple sections 50together in edge to edge relation. The edges of sections 50 aregenerally straight and parallel to allow them to be attached easily,which is generally done by welding in order to seal substrate 14. Theends of sections 50 may also be straight, or may be angled or curved tomatch the shape of the body of water.

Before completing the seams 52 between sections 50, floats 30 areattached to the bottom of sections 50. This may be done either on sitewith sections 50 laid out, in which case floats 30 may be transportedseparately from sections 50 of substrate 14, which will be transportedin a folded or rolled configuration, or may be attached partially orfully by the manufacturer, which will generally require substrate 14 tobe folded with floats 30 in each folded section, as shown in FIG. 17. Iffloats 30 are attached on site, it may be convenient to invert sections50 to provide access to the bottom surface of substrate 14. Preferably,sections 50 are narrow enough to be moved manually and to provide easyaccess to floats 30 as they are being installed. In another example,rather than attaching floats 30 off site, substrate sections 50 may beprovided with holes 56 offsite, making it easier to align and attachfloats 30 as section 50 is unrolled, as shown in FIG. 18. It will beunderstood that any convenient method of attaching floats 30 to thebottom of sections 50 may be used. Once floats 30 are attached tosections 50, sections 50 are properly aligned and attached together. Inorder to allow seam 52 between sections 50 to be properly formed, floats30 are preferably provided with a low height to prevent the materialfrom bunching or pulling away from seam 52, and to ensure substrate 14does not disrupt the flow of water to sump 22. The rest of substrate 14,including the installation of sump 22, tensioners 14/19, etc., may beaccomplished as is known in the art.

Structure 12 is preferably installed above substrate 14 prior to fillingbody of water 16 with water, and must be accomplished in such a mannerthat substrate 14 remains sealed above body of water 16. If used,connectors 44 are also installed at a convenient time. If attached tofloats 30, connectors are preferably installed while section 50 isinverted, or prior to seam 52 being completed. Once structure 12 andfloats 30 are installed, and substrate 14 properly positioned abovewhere body of water 16 will be located, body of water 16 may then befilled with water. It may also be possible to install a cover over anexisting body of water 16, however this will require a different set ofsteps.

In this patent document, the word “comprising” is used in itsnon-limiting sense to mean that items following the word are included,but items not specifically mentioned are not excluded. A reference to anelement by the indefinite article “a” does not exclude the possibilitythat more than one of the elements is present, unless the contextclearly requires that there be one and only one of the elements.

The scope of the following claims should not be limited by the preferredembodiments set forth in the examples above and in the drawings, butshould be given the broadest interpretation consistent with thedescription as a whole.

What is claimed is:
 1. An improved tensioned floating cover thatsupports a structure, the floating cover comprising: a flexible,inelastic, impermeable substrate, the substrate having a bottom face anda top face opposite the bottom face, the substrate extending laterallyacross a surface of a body of water; one or more tensioners that applytension to a tensioned section of the substrate and bias the tensionedsection of the substrate to an installed position on the body of water,the tensioners permitting the substrate to move vertically on a topsurface of the body of water as the volume of water in the body of waterchanges; and a precipitation drainage system for removing water from thetop face of the substrate; the tensioned floating cover beingcharacterized in that: a plurality of floats are affixed to the bottomface of the tensioned section of the substrate, each float having aplanar upper profile and a buoyant force in water, wherein each float isspaced from adjacent floats and dimensioned such that in use, thebuoyant force maintains the upper profile of the floats at anon-disruptive height above the surface of the body of water, thenon-disruptive height being a height at which water flow to theprecipitation drainage system is not disrupted; one or more structuresare rigidly mounted above two or more floats and extend above the topface of the substrate in an upright orientation, the substrate beingsealed between the floats and the structure, the structure having aweight, wherein the buoyant force of the floats acts against the weightof the structure to maintain the substrate immediately adjacent to thefloats above the surface of the body of water; and the one or moretensioners apply sufficient force to maintain the spacing betweenadjacent floats and to maintain the structures in the uprightorientation when acted upon by a predetermined wind load.
 2. Theimproved tensioned floating cover of claim 1, wherein the floats arearranged in a linear or two-dimensional array.
 3. The improved tensionedfloating cover of claim 1, wherein the substrate is made from a materialthat has a tensile strength of at least 100 lb/inch.
 4. The improvedtensioned floating cover of claim 1, wherein the buoyant force maintainsthe substrate immediately adjacent to the floats above the top surfaceby 4 inches or less.
 5. The floating cover of claim 1, wherein thefloats have a height of less than 6 inches, and a volume extendingperpendicular to the height sufficient to provide the buoyant force. 6.The floating cover of claim 1, wherein the floats have a width that isat least 10 times greater than the height.
 7. The floating cover ofclaim 1, wherein the floats comprise moulded bodies, hollow bodies, foamfilled bodies, or laminated structures.
 8. The floating cover of claim1, wherein the floats comprise ballast having a density that is greaterthan or equal to water.
 9. The floating cover of claim 1, wherein one ormore floats are laminated to the bottom face of the substrate.
 10. Thefloating cover of claim 1, wherein one or more floats are affixed byenclosing the floats within cavities formed by a second layer ofmaterial attached to the bottom face of the impermeable substrate. 11.The floating cover of claim 1, wherein the structure is mounted abovethe floats by a mounting comprising an adhesive mounting, a mechanicalmounting, welding, or combination thereof.
 12. The floating cover ofclaim 1, comprising a plurality of structures mounted to a plurality offloats distributed about the substrate.
 13. The floating cover of claim1, wherein the structure comprises a body supported above the substrateby a stand.
 14. The floating cover of claim 13, wherein the standcomprises an assembled frame or a moulded frame.
 15. The floating coverof claim 13, wherein the body is supported by a plurality of standsmounted above a plurality of floats.
 16. The floating cover of claim 1,wherein the structure comprises a support for elongate bodies, awalkway, an access ramp, a working platform, a shelter, a solar module,a decorative element, a shade structure for the body of water, a thermalcollector, an aerator, a water cooler, or a pump.
 17. The floating coverof claim 1, wherein the tensioner comprises length adjustable elementsdistributed along an outer peripheral edge of the substrate.
 18. Thefloating cover of claim 1, wherein the tensioner comprises weightsdistributed about the top face of the substrate.
 19. The floating coverof claim 1, wherein the substrate comprises a plurality of substratesections sealably attached to form the substrate.
 20. The floating coverof claim 1, further comprising stabilizing supports connected betweenadjacent structures to support the structures against wind pressure. 21.The floating cover of claim 20, comprising a plurality of floats andstructures, and wherein the stabilizing supports are connected betweenadjacent structures.
 22. The floating cover of claim 20, comprising aplurality of floats and structures, and wherein the stabilizing supportsare connected between adjacent floats.
 23. The floating cover of claim20, further comprising one or more anchors affixed to the substrate. 24.The floating cover of claim 23, wherein the anchors are buoyant orneutrally buoyant in water.
 25. The floating cover of claim 1, whereinthe force applied by the tensioners permits the substrate to shift underwind loads greater than the predetermined wind load, and returns thesubstrate to the predetermined position relative to the body of waterafter the wind load is reduced to below the predetermined wind load. 26.A floating cover for a body of water, comprising: a flexible, inelastic,impermeable substrate having a bottom face and a top face opposite thebottom face, the substrate being secured laterally across the topsurface; one or more tensioners that apply at least 0.5 lb/lineal footof tension to create a tensioned section of the substrate; aprecipitation drainage system for removing water from the top face ofthe substrate; a plurality of floats having a substantially planar upperprofile, the upper profile being affixed to the bottom face of thetensioned section of the substrate, the floats having a buoyant force inwater; and a structure rigidly mounted above one or more floats, thestructure extending above the top face of the substrate, being sealedbetween the floats and the structure and having a weight, wherein thebuoyant force of the floats acts against the weight of the structure tomaintain the substrate immediately adjacent to the floats above the topsurface of the body of water by 4 inches or less.
 27. A method ofmounting a structure above a floating cover, the method comprising thesteps of: providing a plurality of substrate sections of a flexible,inelastic, impermeable substrate, the substrate sections having a topface, a bottom face, and parallel side edges separated by a width;affixing a plurality of floats to the bottom face of one or moresubstrate sections, the floats having a buoyant force in water, thefloats being low profile and having a substantially planar upper profilethat engages the substrate; rigidly mounting structures to the floatssuch that the structures extend away from the floats and the top face ofthe one or more substrate sections; attaching the plurality of substratesections in edge to edge relation along the parallel side edges to formthe substrate, the floats having a height relative to the width of theat least one section that permits adjacent substrate sections to beattached in edge to edge relation without interfering with theattachment between edges to form a sealed surface; installing thesubstrate on a reservoir and filling the reservoir to form a body ofwater having a surface; applying tension to the substrate to at leastthat portion of the substrate to which floats are affixed, the appliedtension being sufficient to maintain the spacing between adjacent floatsand to maintain the structures in the upright orientation when actedupon by a predetermined wind load.
 28. The method of claim 27, wherein aplurality of floats are affixed to the one or more substrate sectionswith the one or more substrate sections inverted.
 29. The method ofclaim 27, wherein the one or more substrate sections to which the floatsare affixed to the one or more substrate sections offsite.
 30. A methodof mounting a structure above a floating cover, the method comprisingthe steps of: providing a plurality of substrate sections of a flexible,inelastic, impermeable substrate, the substrate sections having a topface, a bottom face, and parallel side edges separated by a width;affixing a plurality of floats to the bottom face of one or moresubstrate sections, the floats having a buoyant force in water, thefloats being low profile and having a substantially planar upper profilethat engages the substrate; rigidly mounting structures to the floatssuch that the structures extend away from the floats and the top face ofthe one or more substrate sections; attaching the plurality of substratesections in edge to edge relation along the parallel side edges to formthe substrate; providing a precipitation drainage system for removingwater from the top face of the substrate; installing the substrate on areservoir and filling the reservoir to form a body of water having asurface, such that the upper profile of the floats is maintained at anon-disruptive height above the surface of the body of water, thenon-disruptive height being a height at which water flow to theprecipitation drainage system is not disrupted; applying tension to thesubstrate to at least that portion of the substrate to which floats areaffixed, the applied tension being sufficient to maintain the spacingbetween adjacent floats, to maintain the structures in the uprightorientation, and maintain the substrate in a predetermined positionrelative to the body of water when acted upon by a predetermined windload, the applied tension permitting the substrate to shift under windloads greater than the predetermined wind load, and returning thesubstrate to the predetermined position relative to the body of waterafter the wind load is reduced to below the predetermined wind load. 31.An improved tensioned floating cover that supports a structure, thefloating cover comprising: a flexible, inelastic, impermeable substrate,the substrate having a bottom face and a top face opposite the bottomface, the substrate extending laterally across a surface of a body ofwater, the substrate being made from a material that has a tensilestrength of at least 100 lb/inch; one or more tensioners that applytension to a tensioned section of the substrate and bias the tensionedsection of the substrate to an installed position on the body of water,the tensioners permitting the substrate to move vertically on a topsurface of the body of water as the volume of water in the body of waterchanges; and a precipitation drainage system for removing water from thetop face of the substrate; the tensioned floating cover beingcharacterized in that: a plurality of floats are affixed to the bottomface of the tensioned section of the substrate in a linear ortwo-dimensional array, each float having a planar upper profile, abuoyant force in water, and a width that is at least 10 times greaterthan the height, wherein each float is spaced from adjacent floats anddimensioned such that in use, the buoyant force maintains the upperprofile of the floats at a non-disruptive height above the surface ofthe body of water, the non-disruptive height being a height at whichwater flow to the precipitation drainage system is not disrupted; aplurality of structures are rigidly mounted above a plurality of floatsdistributed about the substrate, the structures extending above the topface of the substrate in an upright orientation, the structure beingmounted above the floats by a mounting comprising an adhesive mounting,a mechanical mounting, welding, or combination thereof, such that thesubstrate is sealed between the floats and the structure, the structurehaving a weight, wherein the buoyant force of the floats acts againstthe weight of the structure to maintain the substrate immediatelyadjacent to the floats above the surface of the body of water; and theone or more tensioners apply sufficient force to maintain the spacingbetween adjacent floats and to maintain the structures in the uprightorientation when acted upon by a predetermined wind load.